Supercharging process

ABSTRACT

A method for supercharging internal combustion engines by moving supercharged air in a flow path, separating part of the air from the flow path and mixing it with engine exhaust products, directing another portion of the air in the flow path into the chambers of an internal combustion engine to supercharge the engine, and controlling the quantity of air separated from the flow path and mixed with the exhaust in accordance with a quantity of fuel supplied to the internal combustion engine during each cycle. Either single or double diversion may be used. The apparatus for performing the method comprises a compressor which utilizes heated engine exhaust products to compress air for supercharging an engine. A first conduit is connected to the compressor for carrying combustion products from the engine and a second conduit is connected to the compressor to carry air from the compressor to the intake of the engine. At least one additional conduit is provided which connects the first and second conduits to one another for diverting a portion of the compressed air from the second conduit into the exhaust products carried in the first conduit.

United States Patent [111 3,633,358

[72] Inventors Dragos Sfinteanu; Primary Examiner- Douglas Hart MariusAngelo Paul, both of Bucharest, At orney-Spencer & Kaye Romania [21]Appl. No. 836,473 22 Filed June 25 9 9 ABSTRACT: A method forsupercharging internal com- [45] paemed Jam 11, 1972 bustion engines bymoving supercharged air in a flow path, [73] Assignee Uzina 23 Augustseparating part of the air from the flow path and mixing it with engineexhaust products, directing another portion of the air in the flow pathinto the chambers of an internal combustion [54] SUPERCHARGING PROCESSengine to supercharge the engine, and controlling the quantity 11Claims, 3 Drawing Figs. of air separated from the flow path and mixedwith the exhaust in accordance with a quantity of fuel supplied to theinternal US. Cl F02) combustion engine during each cycle. Either singleor double 50] Field of Search 60/13 diversion may be used. The apparatusfor performing the method comprises a compressor which utilizes heatedengine [56] References Cited exhaust products to compress air forsupercharging an engine.

.A first conduit is connected to the compressor for carrying combustionproducts from the engine and a second conduit is 60/13 connected to thecompressor to carry air from the compressor 60/13 to the intake of theengine. At least one additional conduit is 60/13 provided which connectsthe first and second conduits to one 60/13 another for diverting aportion of the compressed air from the 60/13 second conduit into theexhaust products carried in the first conduit.

UNITED STATES PATENTS Iruumvecnou} LINKAGE FOR CYCLICAL MOVEMENTPATENTED Jun 1 1972 3.633; 358

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SUPERCHARGING PROCESS This invention is related to a new highsupercharging process for diesel engines. The purpose of this process isto increase the thermoenergetic parameters of the engine, by reducingthe excess of air, by increasing the chronosection of the admissionprocess (in order to increase the volumetric efficiency), as well as byprotecting the blades of the gas turbine against thermal stress by theexhaust gases.

The present supercharging processes of engines induces, together withthe raise of the supercharging pressure, an increase of the quantity ofair entering the cylinders, thus permitting the increase of the amountof fuel injected during each cycle.

The maximum energetic loading of the cylinders, resulting in reaching amaximum actual mean pressure, could be achieved by employing an amountof air admitted in the cylinders, corresponding to the stoichiometricmixture (the coefficient of excess of air A=I In this case, thetemperature ofthe exhaust gases would reach very high values (for agiven compression ratio).

From the functional point of view, the temperature of the exhaust gasesis limited, first, by the resistance of the material of the turbineblades. At the present level of the technology in the construction ofturbocompressors, these temperatures are of the order of 650-700 C. Thetemperature limit imposes the utilization of high values ofthe excessofair ()\=2...2.2) for the supercharged engines.

This fact is equivalent to leaving out, without utilization, animportant part of the useful cylinder capacity, a fact which constitutesan impediment in the raising of the thermoenergetic performances,irrespective of the engine power.

From the constructive point of view, a large air excess in dieselengines entails large useful volumes of the cylinders, hence largeoverall dimensions and great weight ofthe engine.

The supercharging process by diversion, of twoand fourstroke, singleandmulticylinder internal combustion engines according to the invention,removes the above drawbacks, in that the supercharging air circuitconsists of at least two air branchings, one of which leading the air tothe cylinders ofthe engine while the second one is an air branching,opening in the exhaust pipe, upstream of the gas turbine, the amount ofair branched off being controlled in direct proportion to the load,(quantity of fuel injected, per cycle) by means ofa kinematic connectionwith the injection pump rack, while in a constructive version, the airflow is directed, in the exhaust and admission periods, by anoscillating valve, kinematically connected to the engine distribution,locking the access of air from the supply pipe towards the commonexhaust and admission valve, in parallel with the admission valve(during the admission period).

SUMMARY OF THE INVENTION Among the objects of the present invention isthe provision of apparatus which permits a greater quantity ofair andfuel to be supplied to a given engine and more efficient superchargmg.

A still further object of the invention is an increase in the volumetricefficiency ofthe engine.

A still further object of the invention is the provision of apparatuswhich increases the engine power by reducing the excess of air and byincreasing the volumetric efficiency.

A still further object of the invention is the provision of apparatuswhich is particularly suitable for the high supercharging of singleandmultiple-cylinder engines including twoand four-stroke diesel engines.

Briefly stated these and other objects of the invention are achieved byproviding in the version utilizing simple diversion of the air, asupercharging air circuit which consists of at least two air branchings,of which one leads the air directly to the cylinders of the engine,while the second is an air diversion opening into the exhaust pipe,ahead of the gas turbine. The amount of air diverted is in directproportion to the quantity of fuel injected. By increasing the quantityof fuel injected, an amount of fresh air is allowed to penetrateconcomitantly in the exhaust pipe, the air diluting the exhaust gasesupstream of the turbine, and maintaining their temperature withinadmissible limits (650700 C).

In the version utilizing double diversion of the air, the flow of air,during the exhaust and admission period, is directed by an oscillatingflap, kinematically connected to the engine distribution. During theexhaust period, the performance is similar to that according to thefirst version, while in the admittance period, the penetration of thefresh air into the cylinders through the exhaust valve is insured (inparallel with the admission valve), the exhaust valve remaining openduring the exhaust and admission periods.

FIG. I is a schematic view showing supercharging process by simplediversion of the air flow (two branches of the air supply pipe)according to the present invention.

FIG. 2 is a schematic view of supercharging process by double diversionof the air flow (three branches of the air supply pipe) according toanother embodiment of the invention, the exhaust phase of the enginecycle being shown.

FIG. 2A is a schematic view of the supercharging process by doublediversion as in FIG. 2; the admission phase of the engine cycle beingshown.

The supercharging process by simple diversion, according to FIG. I, isachieved by means of the following elements: engine piston and cylinder1, admission valve 2, exhaust valve 3, admission pipe 4, exhaust pipe 5,diversion pipe 6, regulating valve 7, injection pump rack 8, gas turbine9 and centrifugal compressor 10.

The supercharging process by double diversion, according to the versionin FIGS. 2 and 2A, is achieved by means of the same components as inFIG. 1, to which the diversion pipe 11 and the distribution flap 12 areadded. At the same time, it is to be emphasized, that in this case,component 3 is called exhaust and admission valve.

The internal combustion engines, supercharged by simple diversion,according to FIG. 1, are operated as follows:

The amount of air, supplied by the centrifugal compressor 10, is dividedin two branches, 4 and 6. The amount of air, diverted through the supplypipe 4, penetrates into the cylinder 1 through admission valve 2, whilethe amount of air diverted through pipe 6 penetrates into the exhaustpipe 5. As the amount of fuel injected into the cylinder increases, theexcess of air being reduced accordingly, the temperature of the gasesexhausted through valve 3 increases. In the same proportion, theregulating valve 7, located in the diversion pipe 6, opens, permittingan amount of fresh air to enter the exhaust pipe 5, which air dilutesthe exhaust gases, reducing their temperature, which is thus maintainedbetween limits (650-700 C.) admissible for the functioning of the gasturbine 9 blades. The quantity of air diverted is proportional to theamount of fuel injected per cycle, the stroke of the injection pump rack8 being correlated to the rotation of the adjusting flap 7. As thetemperature of the gases entering the turbine 9 remains constant, andtheir quantity increases, the power developed by the turbine increasesaccordingly, ensuring the increase of the flow of air supplied by thecompressor 10. FIG. 1 represents the functional diagram, for one singlecylinder. The running of the multicylinder engine is similar.

The running of the engines supercharged by double diversion according toFIGS. 2 and 2A is achieved as follows:

The diversion pipe 6 plays the same part as in the previous figure(dilution of the exhausted combustion gases). The diversion pipe 11opens into the exhaust pipe 5, upstream of pipe 6, the confluence crosssection being controlled by means of the distribution flap 12. The pipe11 accomplishes the following functions:

during the exhaust period (FIG. 2) the flap l2 prevents the penetrationof fresh air; this penetrates in the exhaust pipe 5 through thediversion pipe 6, the process being that described in FIG. I.

During the admission period (FIG. 2A), by rotating the flap 12, theaccess of fresh air into cylinder 1 through valve 3 is ensured, thelatter remaining open during this period, in parallel with the admissionvalve 2. Valve 3 works as a common exhaust and admission valve, infunctional succession.

The solution permits to double the chronosection of the admissionperiod, a fact which causes a considerable increase of the volumetricefficiency. The term chronosection represents a value obtained bymultiplying the cross section of the air passage through the admissionvalves by the time which these valves remain open. The exhaust andadmission valve 3 is cooled by the jet of fresh air, passing from thediversion pipe 11 into the cylinder. The motion of the exhaust andadmission valve 3 and of the diversion flap 12 is directed by cams ofadequate profile. i

The advantages of the new supercharging system are as follows:

it ensures the increase of the engine power by increasing the actualmean pressure, due to the diminishing of the excess of air, during thecombustion period.

It ensures the doubling of the chronosection" of the admission process,permitting the increase of the volumetric efficiency and, accordingly,of the engine speed.

it ensures the protection of'the gas turbine against the increasedthermal stress, as a consequence of the diminution in the excess of air,by diluting the exhaust gases, in correlation with the amount of fuelinjected. y

it ensures an efficient cooling of the exhaust valve, by means of thefresh air flowing into the cylinder, near this valve, during theadmission phase.

We claim:

1. A method of supercharging internal combustion engines comprising thesteps of:

a. moving supercharged air in a flow path;

b. separating part of the air from said flow path and mixing it withengine exhaust products;

c. directing another part of the air in said flow path into a combustionchamber of an internal combustion engine to supercharge the engine;

(1. controlling the quantity of air separated from said flow path andmixed with the exhaust in accordance with a quantity of fuel supplied tothe internal combustion engine during each cycle;

c. said engine having a cycle of operation including an exhaust phaseduring which exhaust gases are directed from said combustion chamberthrough an exhaust channel and an admission phase during which air isadmitted to said combustion chamber; and

f. cyclically directing a portion of air from said flow path throughsaid exhaust'channel during said exhaust phase, and directing the sameportion of air toward the engine combustion chamber during saidadmission phase.

2. A method of supercharging internal combustion engines comprising thesteps of:

a. moving supercharged air in a flow path;

b. separating part of the air from said flow path and mixing it withengine exhaust products;

c. directing another part of the air in said flow path into a combustionchamber of an internal combustion engine to supercharge the engine;

d. controlling the quantity of air separated from said flow path andmixed with the exhaust in accordance with a quantity of fuel supplied tothe internal combustion engine during each cycle;

e. driving a compressor with said exhaust products and compressing saidair in said flow path prior to the separating step with said compressor;

f. moving a device for separating said air in said flow path inproportion to the movement ofa device for injecting fuel;

g. said engine having a cycle of operation including an exhaust phaseduring which exhaust gases are directed from said combustion chamberthrough an exhaust channel and an admission phase during which air isadmitted to said combustion chamber;

h. cyclically directing a portion of air from said flow path throughsaid exhaust channel during said exhaust phase, and directing the sameportion of air toward the engine combustion chamber during saidadmission phase; and

i. directing the portion of air of step (f) from said flow pathcontinuously into said exhaust path during the entire engine cycle.

3. A supercharging apparatus comprising, in combination:

a. a compressor means utilizing heated engine exhaust products forcompressing air for supercharging an engine;

b. a first conduit means connected to said compressor means for carryingcombustion products from said engine;

c. a second conduit means for carrying air from said compressor to theintake ofsaid engine;

d. a third conduit means connecting regions of saidfirst and said secondconduit means which are between said compressor and said engine fordiverting a portion of-said compressed air from said second conduit intothe exhaust products carried in said first conduit; and

e. means for diverting compressed air from said second conduit into theexhaust products of said first conduit when an exhaust valve in anengine cylinder to which said first conduit is connected is open and forcyclically diverting the same portion of air in said second conduit intothe said engine cylinder when an admission valve of the engine cylinderis open.

4. A method of supercharging internal combustion engines comprising thesteps of:

a. moving supercharged air in a flow path;

b. separating part of the air from said flow path and mixing it withengine exhaust products;

cfdirecting the air remaining in said flow path after said separatingstep into a combustion chamber of an internal combustion engine tosupercharge the engine;

d. controlling the quantity of air separated from said flow path andmixed with the exhaust in accordance with a quantity of fuel supplied tothe internal combustion engine during each cycle;

e. said engine having a cycle of operation including an exhaust phaseduring which exhaust is directed from said combustion chamber through anexhaust channel and an admission phase during which air is admitted tosaid combustion chamber; and

f. cyclically directing a portion of air from said flow path throughsaid exhaust channel during said exhaust phase, and directing the sameportion of air toward the engine combustion chamber during saidadmission phase.

5. A method of supercharging internal combustion engines comprising thesteps of:

a. moving supercharged air in a flow path;

b. separating part of the air from said flow path and mixing it withengine exhaust products;

c. directing the air remaining in said flow path after said separatingstep into a combustion chamber of an internal combustion engine tosupercharge the engine;

d. controlling the quantity of air separated from said flow path andmixed with the exhaust in accordance with a quantity of fuel supplied tothe internal combustion engine during each cycle;

e. driving a compressor with said exhaust products and compressing saidair in said flow path prior to the separating step with said compressor;

f. moving a device for separating said air in said flow path inproportion to the movement ofa device for injecting fuel;

g. said engine having a cycle of operation including an exhaust phaseduring which exhaust is directed from said combustion chamber through anexhaust channel and an admission phase during which air is admitted tosaid combustion chamber;

h. cyclically directing a portion of air from said flow path throughsaid exhaust channel during said exhaust phase, and directing the sameportion of air toward the engine combustion chamber during saidadmission phase; and

said second conduit means which are between said com pressor and saidengine for diverting a portion of said compressed air from said secondconduit into the exhaust products carried in said first conduit;

. means for controlling the amount of air diverted from said secondconduit to said first conduit in direct proportion to an amount of fuelsupplied to said engine during each cycle; and means for divertingcompressed air from said second conduit into the exhaust products ofsaid first conduit when an exhaust valve in an engine cylinder to whichsaid first conduit is connected is open and for cyclically diverting thesame portion of air in the fiow path into the said engine cylinder whenan admission valve of the engine cylinder is open. t

7. The method of claim 4 including the step of moving a device forseparating air in said flow path by an amount which is proportional to amovement of a device for injecting said fuel.

8. The method of claim 1 including directing the portion of air of step(b) continuously into said exhaust in addition to said portion which isselectively directed into either the exhaust or into the engine chamberduring different portions of the engine cycle.

9. The combination defined in claim 6 wherein said means for controllingthe amount of air diverted include:

i. valve means in said third conduit means for controlling the amount ofair flowing therethrough,

ii. fuel injection means for injecting fuel into cylinders of saidengine, and

iii. proportional linkage means for connecting said fuel injection meanswith said third conduit valve means.

10. The combination defined in claim 3 wherein said cyclical divertingmeans include a fourth conduit connecting portions of said first andsaid second conduits connected to a particular engine cylinder, valvemeans in said fourth conduit, and means connecting said fourthconduit-valve means with the admission and exhaust valves of saidcylinder so as to close said fourth conduit while products are beingexhausted through said first conduit and to open said fourth conduitwhile said admission valve is open.

11. The combination defined in claim 10 including means for controllingthe amount of air directed through said third conduit including: i

i. valve means in said third conduit means for the amount ofair flowingtherethrough,

ii. fuel injection means for injecting fuel into cylinders of saidengine, and

iii. proportional linkage means for connecting said fuel injection meanswith said third conduit valve means.

controlling

1. A method of supercharging internal combustion engines comprising the steps of: a. moving supercharged air in a flow path; b. separating part of the air from said flow path and mixing it with engine exhaust products; c. directing another part of the air in said flow path into a combustion chamber of an internal combustion engine to supercharge the engine; d. controlling the quantity of air separated from said floW path and mixed with the exhaust in accordance with a quantity of fuel supplied to the internal combustion engine during each cycle; e. said engine having a cycle of operation including an exhaust phase during which exhaust gases are directed from said combustion chamber through an exhaust channel and an admission phase during which air is admitted to said combustion chamber; and f. cyclically directing a portion of air from said flow path through said exhaust channel during said exhaust phase, and directing the same portion of air toward the engine combustion chamber during said admission phase.
 2. A method of supercharging internal combustion engines comprising the steps of: a. moving supercharged air in a flow path; b. separating part of the air from said flow path and mixing it with engine exhaust products; c. directing another part of the air in said flow path into a combustion chamber of an internal combustion engine to supercharge the engine; d. controlling the quantity of air separated from said flow path and mixed with the exhaust in accordance with a quantity of fuel supplied to the internal combustion engine during each cycle; e. driving a compressor with said exhaust products and compressing said air in said flow path prior to the separating step with said compressor; f. moving a device for separating said air in said flow path in proportion to the movement of a device for injecting fuel; g. said engine having a cycle of operation including an exhaust phase during which exhaust gases are directed from said combustion chamber through an exhaust channel and an admission phase during which air is admitted to said combustion chamber; h. cyclically directing a portion of air from said flow path through said exhaust channel during said exhaust phase, and directing the same portion of air toward the engine combustion chamber during said admission phase; and i. directing the portion of air of step (f) from said flow path continuously into said exhaust path during the entire engine cycle.
 3. A supercharging apparatus comprising, in combination: a. a compressor means utilizing heated engine exhaust products for compressing air for supercharging an engine; b. a first conduit means connected to said compressor means for carrying combustion products from said engine; c. a second conduit means for carrying air from said compressor to the intake of said engine; d. a third conduit means connecting regions of said first and said second conduit means which are between said compressor and said engine for diverting a portion of said compressed air from said second conduit into the exhaust products carried in said first conduit; and e. means for diverting compressed air from said second conduit into the exhaust products of said first conduit when an exhaust valve in an engine cylinder to which said first conduit is connected is open and for cyclically diverting the same portion of air in said second conduit into the said engine cylinder when an admission valve of the engine cylinder is open.
 4. A method of supercharging internal combustion engines comprising the steps of: a. moving supercharged air in a flow path; b. separating part of the air from said flow path and mixing it with engine exhaust products; c. directing the air remaining in said flow path after said separating step into a combustion chamber of an internal combustion engine to supercharge the engine; d. controlling the quantity of air separated from said flow path and mixed with the exhaust in accordance with a quantity of fuel supplied to the internal combustion engine during each cycle; e. said engine having a cycle of operation including an exhaust phase during which exhaust is directed from said combustion chamber through an exhaust channel and an admission phase during which air is admitted to said combustion chamber; and f. cyclically directing a portion of air from said flow path Through said exhaust channel during said exhaust phase, and directing the same portion of air toward the engine combustion chamber during said admission phase.
 5. A method of supercharging internal combustion engines comprising the steps of: a. moving supercharged air in a flow path; b. separating part of the air from said flow path and mixing it with engine exhaust products; c. directing the air remaining in said flow path after said separating step into a combustion chamber of an internal combustion engine to supercharge the engine; d. controlling the quantity of air separated from said flow path and mixed with the exhaust in accordance with a quantity of fuel supplied to the internal combustion engine during each cycle; e. driving a compressor with said exhaust products and compressing said air in said flow path prior to the separating step with said compressor; f. moving a device for separating said air in said flow path in proportion to the movement of a device for injecting fuel; g. said engine having a cycle of operation including an exhaust phase during which exhaust is directed from said combustion chamber through an exhaust channel and an admission phase during which air is admitted to said combustion chamber; h. cyclically directing a portion of air from said flow path through said exhaust channel during said exhaust phase, and directing the same portion of air toward the engine combustion chamber during said admission phase; and i. directing the portion of air of step (f) from said flow path continuously into said exhaust path during the entire engine cycle.
 6. A supercharging apparatus comprising, in combination: a. a compressor means utilizing heated engine exhaust products for compressing air for supercharging an engine; b. a first conduit means connected to said compressor means for carrying combustion products from said engine; c. a second conduit means for carrying air from said compressor to the intake of said engine; d. a third conduit means connecting regions of said first and said second conduit means which are between said compressor and said engine for diverting a portion of said compressed air from said second conduit into the exhaust products carried in said first conduit; e. means for controlling the amount of air diverted from said second conduit to said first conduit in direct proportion to an amount of fuel supplied to said engine during each cycle; and f. means for diverting compressed air from said second conduit into the exhaust products of said first conduit when an exhaust valve in an engine cylinder to which said first conduit is connected is open and for cyclically diverting the same portion of air in the flow path into the said engine cylinder when an admission valve of the engine cylinder is open.
 7. The method of claim 4 including the step of moving a device for separating air in said flow path by an amount which is proportional to a movement of a device for injecting said fuel.
 8. The method of claim 1 including directing the portion of air of step (b) continuously into said exhaust in addition to said portion which is selectively directed into either the exhaust or into the engine chamber during different portions of the engine cycle.
 9. The combination defined in claim 6 wherein said means for controlling the amount of air diverted include: i. valve means in said third conduit means for controlling the amount of air flowing therethrough, ii. fuel injection means for injecting fuel into cylinders of said engine, and iii. proportional linkage means for connecting said fuel injection means with said third conduit valve means.
 10. The combination defined in claim 3 wherein said cyclical diverting means include a fourth conduit connecting portions of said first and said second conduits connected to a particular engine cylinder, valve means in said fourth conduit, and means connecting said fourth conduit Valve means with the admission and exhaust valves of said cylinder so as to close said fourth conduit while products are being exhausted through said first conduit and to open said fourth conduit while said admission valve is open.
 11. The combination defined in claim 10 including means for controlling the amount of air directed through said third conduit including: i. valve means in said third conduit means for controlling the amount of air flowing therethrough, ii. fuel injection means for injecting fuel into cylinders of said engine, and iii. proportional linkage means for connecting said fuel injection means with said third conduit valve means. 